devices or arrangements, the optical operation of which ismodified by changing the optical properties of the medium of thedevices or arrangements for the control of the intensity,colour, phase, polarisation or direction of light, e.g.switching, gating, modulating or demodulating (1052759)

devices or arrangements, the optical operation of which ismodified by changing the optical properties of the medium of thedevices or arrangements for the control of the intensity,colour, phase, polarisation or direction of light, e.g.switching, gating, modulating or demodulating (1052759)